Antidiabetic Effects of a Standardized Egyptian Rice Bran Extract
Article first published online: 8 MAY 2012
Copyright © 2012 John Wiley & Sons, Ltd.
Volume 27, Issue 2, pages 264–271, February 2013
How to Cite
Kaup, R. M., Khayyal, M. T. and Verspohl, E. J. (2013), Antidiabetic Effects of a Standardized Egyptian Rice Bran Extract. Phytother. Res., 27: 264–271. doi: 10.1002/ptr.4705
- Issue published online: 4 FEB 2013
- Article first published online: 8 MAY 2012
- Manuscript Accepted: 26 MAR 2012
- Manuscript Revised: 19 MAR 2012
- Manuscript Received: 7 DEC 2011
- rice bran;
An extract was prepared from Egyptian stabilized rice bran and standardized to contain 2% γ-oryzanol in addition to its content of other bioactives, notably tocotrienol and policosanol. The standardized extract was found to have a concentration-dependent effect on insulin release in vitro, which, however, is not mediated by γ-tocotrienol in rice bran (detected by HPLC) as could have been expected. Policosanol and γ-oryzanol have insulinotropic effects. The in vitro data of rice bran directly translate into in vivo data of rats by using a glucose tolerance test (increase in plasma insulin). Tocotrienols are well known for their apoptotic effect on tumor cells; nevertheless, an attempt was made to study glucose uptake in HEP-G2 cells, which needs to induce an insulin-resistant state by TNF-α. The Egyptian rice bran extract has an antidiabetic effect. γ-Oryzanol, which is a possible precursor of the insulinotropic compound ferulic acid, is a candidate for this effect. Therefore, it is reasonable to assume that the prevalence of diabetes or at least a prediabetic (type 2) situation can be ameliorated by the investigated rice bran extract. The potential usefulness of the extract as a nutraceutical is currently undergoing more thorough investigations. Copyright © 2012 John Wiley & Sons, Ltd.